Chair for concrete structures



E, M. AND L. M. SCOFIELD. CHAIR FOR CONCRETE STRUCTURES.

APPLICATION FILED JUNE 12. I919.

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CRETE T CT cm ILEDJUNE 12, 19

- Patented Oct. 19,1920.

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) Imm- II 2 liczwdfficyiez EDSON M. SCOFIELDQOF'CHESTER VALLEY, PENNSYLVANIA, AND LYNN mscorrnrn,

OF SAN DIEGO, CALIFORNIA, ASSIGNORS 1T0'SCOFIELD ENGINEERING COMPANY,

01E PHILADELPHIA, PENNSYLVANIA, CORPORATION *OF PENNSYLVANIA.

CHAIR FOR CONCRETE STRUCTURES.

Application filed June 12, 1919. Serial No. 303,551.

To all whom it may concern:

Be it known that we, EDsoN ScorIELo and LYNN M. SooriELD, citizens of the United States, residing in Chester Valley, Pennsylvania, and San Diego, California,

respectively, have invented Chairs for Corr. crete Structures, of which the following 18,

a s )ecification.

ne object of this invention is to provide a chair for temporarily supporting the reinforcing members of a concrete structure, which shall be of such composition as to neither rot nor become corroded after being incorporated in the finished structure and which shall be particularly adapted for properly holding the reinforcing elements in predetermined positions I relatively to wooden or other forms or to each other during the pouring of the concrete ;the invention contemplating a chair which shall not only make a perfect bond with the concrete but which shall be mechanically tied or held within the same so as to prevent access of water to the interior of the finished struc-" ture and more particularly to the reinforcing elements therein.

e also desire to provide a chair of the general type above indicated which shall include novel means whereby it may be held in the desired position Within a form andwhich also shall possess improved means for holding one or more reinforcing elements in definite positions.

These objects and I other advantageous ends we attain as hereinafter 'set' forth, reference being had to the accompanying drawings, in which,

Figure 1 is a fragmentary vertical section Fig. '5 is a plan of the structure shown in Fig. .4;

Fig. 6 is a side elevation partly in section, illustrating our invention with special means whereby it may be positively held to a form; and

Fig. 7 is a side elevation partly in section illustrating a modification of the invention designed to space two substantially parallel reinforcing elements.

In making reinforced concrete structures it'is necessary that the reinforcing bars or elements shall bespaced within theforms in such manner that they will extend at definite distances from the same as well as from each other in order that they may be tioning these elements it has hitherto beencustomary to employ various types of holding devices or chairs which were either made of metal, and were therefore subject to corrosion, or were made of wood or other material liable to rot. As a result channels or passages were formed in the finished concrete structure through which itwas possible for water to gain access to and cause corrosion of the reinforcing elements.

In order to prevent this objectionable action{ and the consequent weakening of the reinforced structure resulting therefrom, we provide, in one of the simpler forms of our Specification er Letters Patent. Patented Oct. 19, 1920.

invention, concrete chairs, of the form and construction shown In Fig. 2. These each consist of a generally cylindrical concrete body 1 having fiat ends and formed with an annular depression or groove 2 in its cylindrical surface, usually about midway between the ends. One of the latter, in this form of the invention, is provided with a transverse depression 3 for the reception of a reinforcing bar 4: which isheld in place by a tie wire 5 embedded in the body of the chair .so that its two ends project from the flat face thereof on oppositersides of said recess 3. Such a chair is particularly adapted to support reinforcing bars at definitev distances from a form 6 and it is obvious that a mass of concrete surrounding the chair will form a perfect bond'therewith as well as mechanically hold the same from movement owing to its entrance into the depressions or recesses 2 and 3, particularly the former. In case it should be desired to employ chairs constructed according to our invention for the purpose of maintaining reinforcing rods at definite distances apart, they would be formed with transverse recesses or depressions 3 in both of their flat faces or ends as illustrated at 7 in Fig. 1 and with a second tie wire 5 embedded in each of them, in a manner similar to that shown in Fig. 2, for the purpose of positively holding the second reinforcing bar 4. If desired or found necessary, as when the chair has considerable length as shown in Fig. 7, more than one of the annular recesses 2 may be provided.

While in some cases the wire tie 5 maybe depended on to properly hold the chair with one of its faces flat against the flat form surface even though this should be vertical rather than horizontal, we may if desired or found advisable, render impossible movement of the chair relatively to the form, and for this purpose construct such chair as shown in Fig. 6. In this case the body or main portion 1 of the chair is of a construction similar to or identical with that shown in Fig. 2 but that face opposite the one having the transverse depression 3 is made with a cylindrical or other extension 9 of such a length as to project completely through the form 6. The outer end of this extension is formed with a transverse slot for the reception of a key 10 so that it is possible to draw the body 1 tightly against the form and maintain it immovahly in such position. After the body of concrete 11 has set, the keys 10 are removed in order to permit of the removal of the forms, and the extensions 9 are then knocked off.

In Figs. 4: and 5 we have illustrated a form of chair 1 which is especially designed to positively hold in place two reinforcing elements a and 11 running at right angles to each other, and for this purpose that end of each chair opposite the one designed to engage the form has two transverse intersecting depressions or recesses 3 and 5 extending at the desired angle to each other, the recess 3 being materially deeper than the recess 3 so that the bar 11 may be carried below but practically in contact with the bar l. As an alternative means for holding the chair to the substantially vertical or other form surface, we may embed in.

that portion of its body adjacent the end designed to engage the form, a length of wire or equivalent material 12 designed to be held to the form 6 by staples or nails 18. This, as well as the other form of our invention, is preferably provided with one or more of the annular grooves 2 and has one or more recesses or depressions formed in its outer end or face for the reception of a reinforcing bar or bars. In case two of the latter are to be spaced as shown in Fig. 4,

the tie wire 5 is so mounted in the body of the chair as to extend diagonally across the superposed bars as shownin Fig. 5.

By the use of chairs of the construction above described the reinforcing bars are supported and held in place during the pouring of the concrete and until the finished structure is completed. By reason of their composition these chairs are non-corrosive and durable, and being of a material simi lar to that composing the body of the finished structure, are not subject to material disintegration or loss of strength, as they become an integral part of the concrete in which they are embedded. In addition, by reason of the annular groove or grooves with which they are formed, our chairs are mechanically keyed or locked to the structure in which they are used so that there is not only a complete prevention of penetration of water or other destructive material to the interior of the structure and a consequent freedom from deterioration of the reinforcing elements but the chairs are immovably held in place. Prior to and during the pouring of the concrete the reinforcing'bars are mechanically bound to the chairs by the tie wires and are so held .in the recesses of said chairs that their shifting or displacement is a practical impossibility.-

We claim:

1. As a new article of manufacture a chair for concrete construction consisting of a substantially cylindrical. body of concrete, having a recess in one end for the reception of a reinforcing bar, and a wire embedded in the body of said chair and projectingon opposite sides of said recess for holding such bar in place, there being an annular recess in the cylindrical body of the chair.

2. As a new article of manufacture a molded concrete chair having a recess for the reception of a reinforcing bar and including an elongated stem for insertion in a form.

3. As a new article of manufacture a molded concrete chair having an extension of reduced cross section for insertion in a form.

4. As a new article of manufacture a molded concrete chair having an extension for insertion in a form; with a key engaging said extension to lock the chair to the form.

5. As a new article of manufacture a chair consisting of a molded body, of concrete provided with a plurality of transverse intersecting recesses for the reception of reinforcing bars and having an annular recess in a plane parallel with that of said first recesses for the reception of the concrete an end for the reception of a reinforcing in which it is embedded. bar.

6. A new article of manufacture consist- In Witness whereof We affix our signa- 10 ing of a molded concrete chair of substantures. I 5 tially cylindrical form having an annular depression in its cylindrical surface and EDSON M. SCOFIELD. having at least one transverse depression in LYNN M. SCOFIELD. 

